package week01;


public class T001 {
	public static void main(String[] args) {
		int a=3,b=5,c=15;
		int a1=999/3,b2=999/5,c2=999/15;
		int sum = shu(a, a1)+shu(b, b2)-shu(c, c2);
		System.out.println(sum);
	}
	
	public static int shu(int x,int y) {
		return (x+x*y)*y/2;
	}
	
}
